Abstract
Experimental data for uranium adsorption on a complex weathered rock
were simulated by twelve modelling teams from eight countries using
surface complexation (SC) models. This intercomparison was part of an
international project to evaluate the present capabilities and
limitations of SC models in representing sorption by geologic materials.
The models were assessed in terms of their predictive ability, data
requirements, number of optimised parameters, ability to simulate
diverse chemical conditions and transferability to other substrates. A
particular aim was to compare the generalised composite (GC) and
component additivity (CA) approaches for modelling sorption by complex
substrates. Both types of SC models showed a promising capability to
simulate sorption data obtained across a range of chemical conditions.
However, the models incorporated a wide variety of assumptions,
particularly in terms of input parameters such as site densities and
surface site types. Furthermore, the methods used to extrapolate the
model simulations to different weathered rock samples collected at the
same field site tended to be unsatisfactory. The outcome of this
modelling exercise provides an overview of the present status of
adsorption modelling in the context of radionuclide migration as
practised in a number of countries worldwide.
Original language | English |
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Pages (from-to) | 651-661 |
Number of pages | 11 |
Journal | Radiochimica Acta |
Volume | 92 |
Issue number | 9-11 |
DOIs | |
Publication status | Published - 2004 |
MoE publication type | A1 Journal article-refereed |
Keywords
- modelling
- radionuclide transport
- sorption
- surface complexation
- uranium